Armchair



FIG. 1 is a front perspective view of an armchair in accordance with my design;

FIG. 2 is a front view thereof;

FIG. 3 is a right side view, with the left side being a mirror image thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof. 

CLAIM The ornamental design for an armchair, as shown and described. 